'Save Our Christmas," screams the Sun, in what must surely rank as one of the oddest campaigns ever to be run by a newspaper. Just as houses are coming out in rashes of bright, sparkling lights, just as the shop windows clog up with fake snow, weird electronic Father Christmases and children are chorusing Away in a Manger, the Sun takes it upon itself to warn us of the dire threat that our Christmas is under.

There's a curious phenomenon in the complex politics of identity that is increasingly evident, and the Sun's campaign is a superlative example: it is how the established majority inverts its status to one of victimhood. So while the odd mishmash of Germanic tribal customs and vestigial religious meaning that gives us Christmas goes from strength to strength in a secular consumer society, we are now told by the Sun that it is under attack by the political correctness of local government's multicultural policies.

The same phenomenon of inverted victimhood is evident in another campaign - that run by Rowan Atkinson against David Blunkett's proposal to extend the law against incitement to racial hatred with a clause to cover religious hatred. Atkinson's intervention has, of course, garnered more coverage in which to explain his muddled grasp of the clause than Blunkett has ever had to explain the very limited measure he is, in fact, proposing. So most people will have been left with a vague but profound sense of unease that our freedom of speech is being curtailed, and that humour and wit about the iniquities of religions will be restricted.

That inverted victimhood quickly takes grip: a Telegraph commentator rallied to the cause this week, accusing the government of "cravenly allowing so-called leaders of the British Muslim minority to alter our fundamental laws". From there, it's a quick slide into absurdity: the British legal system has no competence, the article continued, to "establish when the legitimate expression of fundamentally incompatible faiths tips over into incitement to 'religious hatred'".

So let's take a deep breath, get a grip on the paranoia that lurks in this territory, and be far more realistic about what closing this loophole and making a criminal offence of "incitement to religious hatred" will - and won't - do.

For starters, "religious hatred" is not about having a laugh, or criticising aspects of a religion: it is far more grotesque, and we can't pretend that we don't know the difference; most continents have been scarred by the millions of lives cut short by religious hatred, from Bosnia to Nigeria and India. However, as a legal concept, incitement to religious hatred is complex, which is why it will be the attorney general who considers whether cases meet several criteria before deciding whether to bring a prosecution.

Secondly, the measure (short of a dramatic deterioration) is likely to result in very few prosecutions in this country. The comparable crime of incitement to racial hatred has led in the last three years to 84 cases, of which only four were prosecuted with two convictions. But its value does not just lie in these statistics, but in how the measure has helped to prompt a shift in culture and a new social norm.

The clause on religious hatred lays down the kind of crucial boundary necessary for ordering relations in a multicultural society; as Muslim has become an increasingly important and visible political identity in this country, the state has an urgent responsibility to provide that boundary. With 38% of British Muslims saying they or their family members have experienced Islamophobic comments and insults - this particularly affects women because the hijab makes them easily identifiable - a public association of the state with the unacceptability of Islamophobia is essential.

This clause has an important symbolic role at another level. Minority identities need affirmation and recognition in the public sphere of the state and its institutions; identity is never a private issue but one that must have a public resonance to be meaningful.

Finally, the law provides another weapon in the armoury to combat racism - even if it is one that is rarely used - in all its mutant forms. If this clause does anything constructive, it will choke off that stream of virulent racist propagandathat uses Islamophobia as a cover. If it makes the British National party think twice about its pamphlets, that has to be chalked up as a major merit.

So this clause will serve several important purposes, but I fear that it is increasingly being weighted down with inflated expectations that will ensure, in the end, a measure of disappointment within the Muslim community. In our poll of British Muslims last week, it was interesting how confused respondents were; a huge majority (81%) wanted a law on incitement to religious hatred, and 58% also wanted those who insult or criticise Islam to face criminal prosecution. I suspect that many Muslims hope that the clause will do far more to protect their faith from contempt and abuse than it will.

All religious groups experience the contempt for, ignorance of and lack of interest in religious belief and practice in contemporary, secular Britain, but it weighs particularly heavily on Muslims, whose community is desperately economically deprived (70% of Pakistani and Bangladeshi children live in poverty), and increasingly beleaguered by anti-terrorist legislation. It resonates with their personal experiences of life in marginalised communities and their perception of a suffering Ummah (the international Muslim community) from Chechnya and Iraq to Palestine. What this clause will not do is resolve the vexed issue of the respect for Islam for which many yearn, nor provide relief from the sense of a faith being humiliated and under attack around the globe.

One last set of inflated expectations likely to be disappointed is New Labour's. The clause is part of the government's attempt to shore up its rapidly dwindling Muslim support - the bitter falling out after a generation of political allegiance. That doesn't undermine the clause's validity, only explains the timing. A few vulnerable constituencies (such as Oona King's in Bethnal Green and Bow) are at stake, but Tony Blair also seems to have a personal commitment to trying to neuter the strength of the "clash of civilisations" concept at home (abroad is another issue). He sets aside a surprising amount of time for meeting British Muslim leaders.

It doesn't wash on the streets of Bradford or Bethnal Green, where the anger directed at this government grows daily. Blair is too tainted by his close association with George Bush to ever have credibility with the majority of British Muslims; meanwhile the anti-terrorist measures, detainment, sharp rise in stop and searches, the arrests that rarely lead to charges ... all these are in danger of profoundly alienating Britain's Muslims - and weighed against that, the incitement to religious hatred is a piece of crucial legal housekeeping, but it will do little to win favour, let alone votes.